Elastic holder for cutting-off tools and the like



Dec. 29, 1936. P. BRUNING ELASTIC HOLDER FOR CUTTING-OFF TOOLS AND THE LIKE Filed Fb. 28, 1955 Patented Dec. 29 1936' ELASTIC HOLDER FOR CUTTING-OFF TOOLS AND THE LIKE Paul Briining, Berlin, Germany Application February 28, 1935, Serial No. 8,622 In Germany March 2, 1934 Claims.

This invention relates to tool holders intended for use in connection with lathes and similar machine tools and pertaining to that type of such holders in which the tool can give way 5 elastically if there should arise during the working of the work-piece a resistance of such a strength that the tool or the work-piece or both are exposed to the risk of being damaged or, may be, even broken. My present improved elastic tool holder is distinguished from the known ones, and excels them, by the new feature that the elastic member rendering the tool yielding is constituted by a plate spring, or by a plurality of superposed plate springs respectively, which can be replaced or exchanged and. accommodated to the resistance which the tool must be normally able to stand. Furthermore, it is possible to give the tool an oblique position without afiecting thereby the elastic yieldableness of the same in case of need.

My invention is illustrated diagrammatically and by way of example on the accompanying drawing on which Figure 1 is a side-view of a tool-holder designed according to this invention, the tool (g) being shown in two positions, the one in full lines, the other (g in dotted lines. Figure 2 is a vertical section in the plane :r--y of Fig. 1, seen in the direction from the left to the right in Fig. 1. Figure 3 is a plan of the device, in connection with a lathe chuck (m) and a carrying member (n) for the device, which two parts (m and n) are merely indicated by dotted lines. And Figure 4 is a view similar to Fig. 3, but without said parts shown merely in dotted lines, the foot (a) of the device being assumed to be in another position with respect to Fig. 3. On the drawing, a denotes the said foot or shank member which is attached to the carrying member n of a lathe and can be fixed thereon in various positions, as may be required in any given case. At one end of said foot is an upwardly directed extension I), to the top of which is attached a plurality of superposed plate stances, only one spring will do, viz. if 'an accommodation to work-pieces presenting different 55 but is, or are, nevertheless located in close proximity thereto in horizontal direction, as will 'become obvious from the following part of this specification.

It is also worth mentioning that the springs can be manufactured easily and at low costs, as 5 they can be stamped out of spring sheet-steel of an appropriate thickness. l

The downwardly directed member 0 is practically tubular and has at its lower end a lateral recess 01 for the reception of thetool proper g which is a cutting-off tool in the example shown in Fig. 1, and opposite to said recess there is a lug oz in which an abutment screw 0 is located. Through the member 0 extends a spindle h which is threaded at both ends and is provided at its upper end with a nut di and at its lower end with a nut d. Between this nut and the lower end face of the member 0 is an intermediate piece e which supports the tool 9 from below and serves also as an abutment for the screw 0. The piece 20 e is pressed against said screw and the tool g by said nut d.

The spindle h extends also through the free ends of the springs D1 which are located between calottes i and ii. The bores of the calottes, as well as of the springs, have such a diameterthat there is formed a tubular space p which permits a certain slight oblique position of the member a with the tool 9 relatively to the springs so that the tool can assume, for instance, such a position as that indicated in dotted lines in Fig. 1. Between the upper calotte ii and the upper nut (21 is a suitably shaped washer 1-.

It appears fromFig. 1, that the springs byi are located far above the working edge of the tool g,

, but that said edge is, nevertheless, located not far from the springs in horizontal direction. This arrangement is very suitable for the proper operation of the device as regards the preven- -tion of damages to the tool or to the work-piece 40 or to both, in that the tool is able to give way elastically without getting hooked fast at the work-piece. It is now possible to give the tool g or its equivalent an oblique position, for instance like the position g1, and in every position the tool can be used up 'in' its entire length without a repeated welding, the only requirement being repeated grinding of the cutting edge.

I claim:

1. An elastic holder for cutting-oil tools and the like, comprising, in combination, an upwardly directed member adapted to be attached to the tool holder of a lathe or the like, a downwardly directed member located adjacent to said firstmentioned member and being at its lower end 56 adapted to receive the tool proper,- and a plate spring extending horizontally from the upwardly extending member to the downwardly extending one and being connected therewith, said downwardly directed member comprising a body portion so designed at its top face as to be adapted to receive there an inverted calotte, an upright V calotte arranged above said first calotte, the adjacent end of the spring being perforated and located between said calottes, and means for holding all these members together.

2. An elastic holder for cutting-of! toolsiand the like comprising, in combination, an upwardly directed member adapted to be attached to the tool holder of a lathe or the like, a downwardly directed member located adjacent thereto and comprising, in turn, a body portion so designed at its lower end as to beradapted to receive there the tool proper and so designed at its upper face as to be adapted to receive an inverted calotte, another calotte located above said first calotte. remote therefrom, a horizontal spring extending from the top of the upwardly directed member to the top of the downwardly directed member. and having at this end a bore and taking with this end between calottes, the flat faces of which contact with said spring, said calotteshaving bores corresponding with the bore of said spring, and 9.

spindle extending through the body of the downwardly directed member andthrough said bore and having a smaller diameter than the said bores.

3. A cutting of! tool and the like, comprising a i shank member'for securing the tool to a lathe, an upwardly extendingmember secured to the first-mentioned member, a. downwardly extending member to which a cutting tool is adapted to besecured, and a plate springsecured to the upwardly and downwardly extending members to.

which means are provided on each extending. member to secure the springs to said extending members.

, PAUL BRUNING. 

